Bonding in Coordination Compounds MCQ Quiz in मराठी - Objective Question with Answer for Bonding in Coordination Compounds - मोफत PDF डाउनलोड करा

Concept:

Valence bond theory - 

• According to the theory, metal atom or ion under influence of ligands can use their empty orbitals for hybridisation.
• This will give rise to set of equivalent orbitals of definite geometry.
• The hybrid orbital can overlap with the ligands where ligands can donate electrons for bonding.
• Basis on the presence of unpaired electron in the complex the theory give the nature of the complex as paramagnetic or diamagnetic.

Limitation of the theory includes -

1. It fails to explain the high spin and low spin complexes.
2. It fails to explain the colour and spectra of the complexes.
3. It fails to give an adequate reason for inner and outer orbital complexes.

Explanation:

According to VBT the complex [Co(OH2)6|2+ ,

• Electronic configuration of Co(27) is [Ar]3d⁷4s².
• As in the complex Co is in +2 oxidation state, the configuration of Co²⁺ is [Ar] 3d⁷ 4s⁰.

According to given condition, the complex has one unpaired electron, so, pairing occurs and the orbital configuration is -

→ d- orbital involve in formation of the complex [Co(OH2)6|2+ or in hybridization is outer d-orbital.

→ Thus, the hybridization is sp³d².

→ The complex is octahedral.

→ Due to the presence of one unpaired electron the complex is paramagnetic in nature.

Conclusion:

Thus, for the complex [Co(OH2)6|2+, statements (i) & (ii) i.e. 'the complex is octahedral" and "the complex is outer orbital complex are true".

Hence the correct answer is option 3.

Correct answer: 2)

Concept:

• A spectrochemical series is nothing but a list of ligands ordered on ligand strength (ability) and a list of metal ions based on oxidation number, group and its identity.
• In crystal field theory, ligands modify the difference in energy between the d orbital / triangle, called the ligand-field splitting parameter for ligands or the crystal-field splitting parameter, which is mainly observed in differences in colour of similar metal-ligand complexes.
• A strong field ligand has high crystal field stabilisation energy.
• The complexes formed in this are called low spin complexes.
• They are mostly diamagnetic or less paramagnetic than weak fields.
• A weak ligand has lower CFSE.
• The complexes formed with these ligands are also known as high spin complexes.
• They are mostly paramagnetic in nature.

Explanation:

• High spin and low spin complex are determined by magnitude of CFSE.
• The energy of t_2g orbital is lowered by 0.4\(\Delta _{o}\) and energy of e_g orbital is raised by 0.6\(\Delta _{o}\).
• If the ligand is strong field, then splitting will be greater. Thus, have high CFSE. 
• In that case, pairing energy cannot overcome the CFSE and the electrons get paired in lower orbitals. 
• So, as the electrons get paired, fewer electrons will be left (in case of d⁷ configuration) for e_g orbital.
• Thus, the d⁷ configuration for strong field ligands is as: 

• CFSE= energy difference between two sets of orbitals
• CFSE= Energy of lower set - energy of higher set
• CFSE= (0.4 x 6)-(0.6 x 1)
• CFSE= 1.8\(\Delta _{o}\)
• In case of weak field ligand, pairing will not be done.
• Thus, the d⁷ configuration for weak field ligands is as: 

• CFSE= (0.4 x 5)-(0.6 x 2)
• CFSE= 0.8\(\Delta _{o}\)

Conclusion:

Thus, in weak and strong fields the (CFSE), Δ0 for a metal ion with d7 electronic configuration are 0.8 Δ0 and 1.8 Δ0, respectively

Correct answer: 2)

Concept:

• A spectrochemical series is nothing but a list of ligands ordered on ligand strength (ability) and a list of metal ions based on oxidation number, group and its identity.
• In crystal field theory, ligands modify the difference in energy between the d orbital / triangle, called the ligand-field splitting parameter for ligands or the crystal-field splitting parameter, which is mainly observed in differences in colour of similar metal-ligand complexes.
• A strong field ligand has high crystal field stabilisation energy.
• The complexes formed in this are called low spin complexes.
• They are mostly diamagnetic or less paramagnetic than weak fields.
• A weak ligand has lower CFSE.
• The complexes formed with these ligands are also known as high spin complexes.
• They are mostly paramagnetic in nature.

Explanation:

• High spin and low spin complex are determined by magnitude of CFSE.
• The energy of t_2g orbital is lowered by 0.4\(\Delta _{o}\) and energy of e_g orbital is raised by 0.6\(\Delta _{o}\).
• If the ligand is strong field, then splitting will be greater. Thus, have high CFSE. 
• In that case, pairing energy cannot overcome the CFSE and the electrons get paired in lower orbitals. 
• So, as the electrons get paired, fewer electrons will be left (in case of d⁷ configuration) for e_g orbital.
• Thus, the d⁷ configuration for strong field ligands is as: 

• CFSE= energy difference between two sets of orbitals
• CFSE= Energy of lower set - energy of higher set
• CFSE= (0.4 x 6)-(0.6 x 1)
• CFSE= 1.8\(\Delta _{o}\)
• In case of weak field ligand, pairing will not be done.
• Thus, the d⁷ configuration for weak field ligands is as: 

• CFSE= (0.4 x 5)-(0.6 x 2)
• CFSE= 0.8\(\Delta _{o}\)

Conclusion:

Thus, in weak and strong fields the (CFSE), Δ0 for a metal ion with d7 electronic configuration are 0.8 Δ0 and 1.8 Δ0, respectively

Correct answer: 4)

Concept:

• The Crystal Field Theory is more widely accepted than the valence bond theory.
• It assumes that the attraction between the central metal and the ligands in a complex is purely electrostatic.
• In the crystal field the following assumptions are made : (i) Ligands are treated as point charges. (ii) There is no interaction between metal orbitals and ligand orbitals. (iii) The d orbitals on the metal all have the same energy (that is degenerate) in the free atom.
• However, when a complex is formed the ligands destroy the degeneracy of these orbitals, i.e. the orbitals now have different energies. 

Explanation:

• The power for splitting the metal d orbitals is higher for strong ligands than for weaker ligands. 
• Spectrochemical series arranges the ligands based on their splitting powers.
• Ligands are classified as strong or weak based on the spectrochemical series:
• I^- < Br^- < Cl^- < SCN^- < F^- < OH^- < ox^2-< ONO^- < H₂O < SCN^- < EDTA^4- < NH₃ < en < NO₂^- < CN^-
• The crystal field-splitting for Cr³⁺ ion in octahedral field increases for ligands I⁻,H₂​O,NH₃​,CN⁻ and the order is I⁻2​O3​−.
• This is in accordance with spectrochemical series.

Conclusion:

Thus, In the octahedral crystal field, the correct order of splitting in Cr3+ complexes for I- is H2O, NH3 and CN- is I−2​O3​−

Concept:

Valence bond theory - 

• According to the theory, metal atom or ion under influence of ligands can use their empty orbitals for hybridisation.
• This will give rise to set of equivalent orbitals of definite geometry.
• The hybrid orbital can overlap with the ligands where ligands can donate electrons for bonding.
• Basis on the presence of unpaired electron in the complex the theory give the nature of the complex as paramagnetic or diamagnetic.

Limitation of the theory includes -

1. It fails to explain the high spin and low spin complexes.
2. It fails to explain the colour and spectra of the complexes.
3. It fails to give an adequate reason for inner and outer orbital complexes.

Explanation:

According to VBT the complex [Co(OH2)6|2+ ,

• Electronic configuration of Co(27) is [Ar]3d⁷4s².
• As in the complex Co is in +2 oxidation state, the configuration of Co²⁺ is [Ar] 3d⁷ 4s⁰.

According to given condition, the complex has one unpaired electron, so, pairing occurs and the orbital configuration is -

→ d- orbital involve in formation of the complex [Co(OH2)6|2+ or in hybridization is outer d-orbital.

→ Thus, the hybridization is sp³d².

→ The complex is octahedral.

→ Due to the presence of one unpaired electron the complex is paramagnetic in nature.

Conclusion:

Thus, for the complex [Co(OH2)6|2+, statements (i) & (ii) i.e. 'the complex is octahedral" and "the complex is outer orbital complex are true".

Hence the correct answer is option 3.

Correct answer: 2)

Concept:

• A spectrochemical series is nothing but a list of ligands ordered on ligand strength (ability) and a list of metal ions based on oxidation number, group and its identity.
• In crystal field theory, ligands modify the difference in energy between the d orbital / triangle, called the ligand-field splitting parameter for ligands or the crystal-field splitting parameter, which is mainly observed in differences in colour of similar metal-ligand complexes.
• A strong field ligand has high crystal field stabilisation energy.
• The complexes formed in this are called low spin complexes.
• They are mostly diamagnetic or less paramagnetic than weak fields.
• A weak ligand has lower CFSE.
• The complexes formed with these ligands are also known as high spin complexes.
• They are mostly paramagnetic in nature.

Explanation:

• High spin and low spin complex are determined by magnitude of CFSE.
• The energy of t_2g orbital is lowered by 0.4\(\Delta _{o}\) and energy of e_g orbital is raised by 0.6\(\Delta _{o}\).
• If the ligand is strong field, then splitting will be greater. Thus, have high CFSE. 
• In that case, pairing energy cannot overcome the CFSE and the electrons get paired in lower orbitals. 
• So, as the electrons get paired, fewer electrons will be left (in case of d⁷ configuration) for e_g orbital.
• Thus, the d⁷ configuration for strong field ligands is as: 

• CFSE= energy difference between two sets of orbitals
• CFSE= Energy of lower set - energy of higher set
• CFSE= (0.4 x 6)-(0.6 x 1)
• CFSE= 1.8\(\Delta _{o}\)
• In case of weak field ligand, pairing will not be done.
• Thus, the d⁷ configuration for weak field ligands is as: 

• CFSE= (0.4 x 5)-(0.6 x 2)
• CFSE= 0.8\(\Delta _{o}\)

Conclusion:

Thus, in weak and strong fields the (CFSE), Δ0 for a metal ion with d7 electronic configuration are 0.8 Δ0 and 1.8 Δ0, respectively

Concept:

Valence bond theory - 

• According to the theory, metal atom or ion under influence of ligands can use their empty orbitals for hybridisation.
• This will give rise to set of equivalent orbitals of definite geometry.
• The hybrid orbital can overlap with the ligands where ligands can donate electrons for bonding.
• Basis on the presence of unpaired electron in the complex the theory give the nature of the complex as paramagnetic or diamagnetic.

Limitation of the theory includes -

1. It fails to explain the high spin and low spin complexes.
2. It fails to explain the colour and spectra of the complexes.
3. It fails to give an adequate reason for inner and outer orbital complexes.

Explanation:

According to VBT the complex [Co(OH2)6|2+ ,

• Electronic configuration of Co(27) is [Ar]3d⁷4s².
• As in the complex Co is in +2 oxidation state, the configuration of Co²⁺ is [Ar] 3d⁷ 4s⁰.

According to given condition, the complex has one unpaired electron, so, pairing occurs and the orbital configuration is -

→ d- orbital involve in formation of the complex [Co(OH2)6|2+ or in hybridization is outer d-orbital.

→ Thus, the hybridization is sp³d².

→ The complex is octahedral.

→ Due to the presence of one unpaired electron the complex is paramagnetic in nature.

Conclusion:

Thus, for the complex [Co(OH2)6|2+, statements (i) & (ii) i.e. 'the complex is octahedral" and "the complex is outer orbital complex are true".

Hence the correct answer is option 3.

Concept:

Valence bond theory - 

• According to the theory, metal atom or ion under influence of ligands can use their empty orbitals for hybridisation.
• This will give rise to set of equivalent orbitals of definite geometry.
• The hybrid orbital can overlap with the ligands where ligands can donate electrons for bonding.
• Basis on the presence of unpaired electron in the complex the theory give the nature of the complex as paramagnetic or diamagnetic.

Limitation of the theory includes -

1. It fails to explain the high spin and low spin complexes.
2. It fails to explain the colour and spectra of the complexes.
3. It fails to give an adequate reason for inner and outer orbital complexes.

Explanation:

According to VBT the complex [Co(OH2)6|2+ ,

• Electronic configuration of Co(27) is [Ar]3d⁷4s².
• As in the complex Co is in +2 oxidation state, the configuration of Co²⁺ is [Ar] 3d⁷ 4s⁰.

According to given condition, the complex has one unpaired electron, so, pairing occurs and the orbital configuration is -

→ d- orbital involve in formation of the complex [Co(OH2)6|2+ or in hybridization is outer d-orbital.

→ Thus, the hybridization is sp³d².

→ The complex is octahedral.

→ Due to the presence of one unpaired electron the complex is paramagnetic in nature.

Conclusion:

Thus, for the complex [Co(OH2)6|2+, statements (i) & (ii) i.e. 'the complex is octahedral" and "the complex is outer orbital complex are true".

Hence the correct answer is option 3.

Concept:

Valence bond theory - 

• According to the theory, metal atom or ion under influence of ligands can use their empty orbitals for hybridisation.
• This will give rise to set of equivalent orbitals of definite geometry.
• The hybrid orbital can overlap with the ligands where ligands can donate electrons for bonding.
• Basis on the presence of unpaired electron in the complex the theory give the nature of the complex as paramagnetic or diamagnetic.

Limitation of the theory includes -

1. It fails to explain the high spin and low spin complexes.
2. It fails to explain the colour and spectra of the complexes.
3. It fails to give an adequate reason for inner and outer orbital complexes.

Explanation:

According to VBT the complex [Co(OH2)6|2+ ,

• Electronic configuration of Co(27) is [Ar]3d⁷4s².
• As in the complex Co is in +2 oxidation state, the configuration of Co²⁺ is [Ar] 3d⁷ 4s⁰.

According to given condition, the complex has one unpaired electron, so, pairing occurs and the orbital configuration is -

→ d- orbital involve in formation of the complex [Co(OH2)6|2+ or in hybridization is outer d-orbital.

→ Thus, the hybridization is sp³d².

→ The complex is octahedral.

→ Due to the presence of one unpaired electron the complex is paramagnetic in nature.

Conclusion:

Thus, for the complex [Co(OH2)6|2+, statements (i) & (ii) i.e. 'the complex is octahedral" and "the complex is outer orbital complex are true".

Hence the correct answer is option 3.

Correct answer: 2)

Concept:

• A spectrochemical series is nothing but a list of ligands ordered on ligand strength (ability) and a list of metal ions based on oxidation number, group and its identity.
• In crystal field theory, ligands modify the difference in energy between the d orbital / triangle, called the ligand-field splitting parameter for ligands or the crystal-field splitting parameter, which is mainly observed in differences in colour of similar metal-ligand complexes.
• A strong field ligand has high crystal field stabilisation energy.
• The complexes formed in this are called low spin complexes.
• They are mostly diamagnetic or less paramagnetic than weak fields.
• A weak ligand has lower CFSE.
• The complexes formed with these ligands are also known as high spin complexes.
• They are mostly paramagnetic in nature.

Explanation:

• High spin and low spin complex are determined by magnitude of CFSE.
• The energy of t_2g orbital is lowered by 0.4\(\Delta _{o}\) and energy of e_g orbital is raised by 0.6\(\Delta _{o}\).
• If the ligand is strong field, then splitting will be greater. Thus, have high CFSE. 
• In that case, pairing energy cannot overcome the CFSE and the electrons get paired in lower orbitals. 
• So, as the electrons get paired, fewer electrons will be left (in case of d⁷ configuration) for e_g orbital.
• Thus, the d⁷ configuration for strong field ligands is as: 

• CFSE= energy difference between two sets of orbitals
• CFSE= Energy of lower set - energy of higher set
• CFSE= (0.4 x 6)-(0.6 x 1)
• CFSE= 1.8\(\Delta _{o}\)
• In case of weak field ligand, pairing will not be done.
• Thus, the d⁷ configuration for weak field ligands is as: 

• CFSE= (0.4 x 5)-(0.6 x 2)
• CFSE= 0.8\(\Delta _{o}\)

Conclusion:

Thus, in weak and strong fields the (CFSE), Δ0 for a metal ion with d7 electronic configuration are 0.8 Δ0 and 1.8 Δ0, respectively